Assessment of genetic diversity among Bambara groundnut lines using SSR markers

Abstract Evaluating available genetic diversity is important for crop improvement especially in neglected crops such as Bambara groundnut. The objective was to characterise genetic variation among 19 Bambara groundnut lines using 20 simple sequence repeat (SSR) markers for initiating Bambara groundnut improvement in South Africa. Genomic DNA was extracted from leaf samples of each genotype and genotyped with diagnostic SSR markers. The SSR fragments were scored numerically as codominant before the genetic parameters were calculated using GenAlex software. The markers exhibited an average polymorphic information content (PIC) of 0.57. Similarly, the observed heterozygosity among the lines was 0.58, showing some level of outcrossing. The first two principal components explained 65.2% of the variation among the genotypes and grouped the genotypes into three clusters. The shortest genetic distance was zero between genotypes Brown and Light brown while Tiganecuru and S19 were farthest related genotypes (0.60). Lines such as IITA686, Cream and Uniswa Red-R that had good performance for multiple agronomic traits occurred within 0.40 genetic distance making them genetically divergent enough for developing breeding populations for Bambara groundnut improvement. The most divergent genotypes with favourable agro-morphological characteristics will be recommended as genetic resources for Bambara improvement and variety development programs.